/*
 * Copyright 2011 The Rusted Roof, LLC.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package org.proteusframework.platformservice.grammar;

import org.proteusframework.platformservice.grammar.expression.IExpression;
import org.proteusframework.platformservice.grammar.generated.ParseException;
import org.proteusframework.platformservice.grammar.generated.SimpleExpressionParser;

import java.io.Reader;

/**
 * A ExpressionParser implementation that uses the expression parser generated by JavaCC
 */
public final class ExpressionParserManager
{

    private ExpressionParserManager()
    {

    }

    public static IExpressionParser createParser()
    {
        return new IExpressionParser()
        {
            @Override
            public IExpression parse(Reader statementReader) throws IllegalExpressionException
            {
                SimpleExpressionParser parser = new SimpleExpressionParser(statementReader);
                try
                {
                    return parser.Expression();
                } catch (ParseException e)
                {
                    throw new IllegalExpressionException(e);
                }
            }
        };
    }
}
